/*

 * H.26L/H.264/AVC/JVT/14496-10/... decoder

 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * H.264 / AVC / MPEG-4 part10 codec.

 * @author Michael Niedermayer <michaelni@gmx.at>

 */

#define UNCHECKED_BITSTREAM_READER 1

#include "config_components.h"

#include "libavutil/attributes.h"

#include "libavutil/avassert.h"

#include "libavutil/emms.h"

#include "libavutil/imgutils.h"

#include "libavutil/mem.h"

#include "libavutil/opt.h"

#include "libavutil/thread.h"

#include "libavutil/video_enc_params.h"

#include "codec_internal.h"

#include "internal.h"

#include "error_resilience.h"

#include "avcodec.h"

#include "h264.h"

#include "h264dec.h"

#include "h2645_parse.h"

#include "h264data.h"

#include "h264_ps.h"

#include "golomb.h"

#include "hwaccel_internal.h"

#include "hwconfig.h"

#include "mpegutils.h"

#include "profiles.h"

#include "rectangle.h"

#include "libavutil/refstruct.h"

#include "thread.h"

#include "threadframe.h"

const uint16_t ff_h264_mb_sizes[4] = { 256, 384, 512, 768 };

int avpriv_h264_has_num_reorder_frames(AVCodecContext *avctx)

{

    H264Context *h = avctx->priv_data;

    return h && h->ps.sps ? h->ps.sps->num_reorder_frames : 0;

}

static void h264_er_decode_mb(void *opaque, int ref, int mv_dir, int mv_type,

                              int (*mv)[2][4][2],

                              int mb_x, int mb_y, int mb_intra, int mb_skipped)

{

    const H264Context *h = opaque;

    H264SliceContext *sl = &h->slice_ctx[0];

    sl->mb_x = mb_x;

    sl->mb_y = mb_y;

    sl->mb_xy = mb_x + mb_y * h->mb_stride;

    memset(sl->non_zero_count_cache, 0, sizeof(sl->non_zero_count_cache));

    av_assert1(ref >= 0);

    /* FIXME: It is possible albeit uncommon that slice references

     * differ between slices. We take the easy approach and ignore

     * it for now. If this turns out to have any relevance in

     * practice then correct remapping should be added. */

    if (ref >= sl->ref_count[0])

        ref = 0;

    if (!sl->ref_list[0][ref].data[0]) {

        av_log(h->avctx, AV_LOG_DEBUG, "Reference not available for error concealing\n");

        ref = 0;

    }

    if ((sl->ref_list[0][ref].reference&3) != 3) {

        av_log(h->avctx, AV_LOG_DEBUG, "Reference invalid\n");

        return;

    }

    fill_rectangle(&h->cur_pic.ref_index[0][4 * sl->mb_xy],

                   2, 2, 2, ref, 1);

    fill_rectangle(&sl->ref_cache[0][scan8[0]], 4, 4, 8, ref, 1);

    fill_rectangle(sl->mv_cache[0][scan8[0]], 4, 4, 8,

                   pack16to32((*mv)[0][0][0], (*mv)[0][0][1]), 4);

    sl->mb_mbaff =

    sl->mb_field_decoding_flag = 0;

    ff_h264_hl_decode_mb(h, &h->slice_ctx[0]);

}

void ff_h264_draw_horiz_band(const H264Context *h, H264SliceContext *sl,

                             int y, int height)

{

    AVCodecContext *avctx = h->avctx;

    const AVFrame   *src  = h->cur_pic.f;

    const AVPixFmtDescriptor *desc;

    int offset[AV_NUM_DATA_POINTERS];

    int vshift;

    const int field_pic = h->picture_structure != PICT_FRAME;

    if (!avctx->draw_horiz_band)

        return;

    if (field_pic && h->first_field && !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD))

        return;

    if (field_pic) {

        height <<= 1;

        y      <<= 1;

    }

    height = FFMIN(height, avctx->height - y);

    desc   = av_pix_fmt_desc_get(avctx->pix_fmt);

    vshift = desc->log2_chroma_h;

    offset[0] = y * src->linesize[0];

    offset[1] =

    offset[2] = (y >> vshift) * src->linesize[1];

    for (int i = 3; i < AV_NUM_DATA_POINTERS; i++)

        offset[i] = 0;

    emms_c();

    avctx->draw_horiz_band(avctx, src, offset,

                           y, h->picture_structure, height);

}

void ff_h264_free_tables(H264Context *h)

{

    int i;

    av_freep(&h->intra4x4_pred_mode);

    av_freep(&h->chroma_pred_mode_table);

    av_freep(&h->cbp_table);

    av_freep(&h->mvd_table[0]);

    av_freep(&h->mvd_table[1]);

    av_freep(&h->direct_table);

    av_freep(&h->non_zero_count);

    av_freep(&h->slice_table_base);

    h->slice_table = NULL;

    av_freep(&h->list_counts);

    av_freep(&h->mb2b_xy);

    av_freep(&h->mb2br_xy);

    av_refstruct_pool_uninit(&h->qscale_table_pool);

    av_refstruct_pool_uninit(&h->mb_type_pool);

    av_refstruct_pool_uninit(&h->motion_val_pool);

    av_refstruct_pool_uninit(&h->ref_index_pool);

#if CONFIG_ERROR_RESILIENCE

    av_freep(&h->er.mb_index2xy);

    av_freep(&h->er.error_status_table);

    av_freep(&h->er.er_temp_buffer);

    av_freep(&h->dc_val_base);

#endif

    for (i = 0; i < h->nb_slice_ctx; i++) {

        H264SliceContext *sl = &h->slice_ctx[i];

        av_freep(&sl->bipred_scratchpad);

        av_freep(&sl->edge_emu_buffer);

        av_freep(&sl->top_borders[0]);

        av_freep(&sl->top_borders[1]);

        sl->bipred_scratchpad_allocated = 0;

        sl->edge_emu_buffer_allocated   = 0;

        sl->top_borders_allocated[0]    = 0;

        sl->top_borders_allocated[1]    = 0;

    }

}

int ff_h264_alloc_tables(H264Context *h)

{

    ERContext *const er = &h->er;

    const int big_mb_num = h->mb_stride * (h->mb_height + 1);

    const int row_mb_num = 2*h->mb_stride*FFMAX(h->nb_slice_ctx, 1);

    const int st_size = big_mb_num + h->mb_stride;

    int x, y;

    if (!FF_ALLOCZ_TYPED_ARRAY(h->intra4x4_pred_mode,     row_mb_num * 8)  ||

        !FF_ALLOCZ_TYPED_ARRAY(h->non_zero_count,         big_mb_num)      ||

        !FF_ALLOCZ_TYPED_ARRAY(h->slice_table_base,       st_size)         ||

        !FF_ALLOCZ_TYPED_ARRAY(h->cbp_table,              big_mb_num)      ||

        !FF_ALLOCZ_TYPED_ARRAY(h->chroma_pred_mode_table, big_mb_num)      ||

        !FF_ALLOCZ_TYPED_ARRAY(h->mvd_table[0],           row_mb_num * 8)  ||

        !FF_ALLOCZ_TYPED_ARRAY(h->mvd_table[1],           row_mb_num * 8)  ||

        !FF_ALLOCZ_TYPED_ARRAY(h->direct_table,           big_mb_num * 4)  ||

        !FF_ALLOCZ_TYPED_ARRAY(h->list_counts,            big_mb_num)      ||

        !FF_ALLOCZ_TYPED_ARRAY(h->mb2b_xy,                big_mb_num)      ||

        !FF_ALLOCZ_TYPED_ARRAY(h->mb2br_xy,               big_mb_num))

        return AVERROR(ENOMEM);

    h->slice_ctx[0].intra4x4_pred_mode = h->intra4x4_pred_mode;

    h->slice_ctx[0].mvd_table[0] = h->mvd_table[0];

    h->slice_ctx[0].mvd_table[1] = h->mvd_table[1];

    memset(h->slice_table_base, -1,

           st_size * sizeof(*h->slice_table_base));

    h->slice_table = h->slice_table_base + h->mb_stride * 2 + 1;

    for (y = 0; y < h->mb_height; y++)

        for (x = 0; x < h->mb_width; x++) {

            const int mb_xy = x + y * h->mb_stride;

            const int b_xy  = 4 * x + 4 * y * h->b_stride;

            h->mb2b_xy[mb_xy]  = b_xy;

            h->mb2br_xy[mb_xy] = 8 * (FMO ? mb_xy : (mb_xy % (2 * h->mb_stride)));

        }

    if (CONFIG_ERROR_RESILIENCE) {

        const int er_size = h->mb_height * h->mb_stride * (4*sizeof(int) + 1);

        int mb_array_size = h->mb_height * h->mb_stride;

        int y_size  = (2 * h->mb_width + 1) * (2 * h->mb_height + 1);

        int yc_size = y_size + 2 * big_mb_num;

        /* init ER */

        er->avctx          = h->avctx;

        er->decode_mb      = h264_er_decode_mb;

        er->opaque         = h;

        er->quarter_sample = 1;

        er->mb_num      = h->mb_num;

        er->mb_width    = h->mb_width;

        er->mb_height   = h->mb_height;

        er->mb_stride   = h->mb_stride;

        er->b8_stride   = h->mb_width * 2 + 1;

        // error resilience code looks cleaner with this

        if (!FF_ALLOCZ_TYPED_ARRAY(er->mb_index2xy,        h->mb_num + 1) ||

            !FF_ALLOCZ_TYPED_ARRAY(er->error_status_table, mb_array_size) ||

            !FF_ALLOCZ_TYPED_ARRAY(er->er_temp_buffer,     er_size)       ||

            !FF_ALLOCZ_TYPED_ARRAY(h->dc_val_base,         yc_size))

            return AVERROR(ENOMEM); // ff_h264_free_tables will clean up for us

        for (y = 0; y < h->mb_height; y++)

            for (x = 0; x < h->mb_width; x++)

                er->mb_index2xy[x + y * h->mb_width] = x + y * h->mb_stride;

        er->mb_index2xy[h->mb_height * h->mb_width] = (h->mb_height - 1) *

                                                      h->mb_stride + h->mb_width;

        er->dc_val[0] = h->dc_val_base + h->mb_width * 2 + 2;

        er->dc_val[1] = h->dc_val_base + y_size + h->mb_stride + 1;

        er->dc_val[2] = er->dc_val[1] + big_mb_num;

        for (int i = 0; i < yc_size; i++)

            h->dc_val_base[i] = 1024;

    }

    return 0;

}

/**

 * Init slice context

 */

void ff_h264_slice_context_init(H264Context *h, H264SliceContext *sl)

{

    sl->ref_cache[0][scan8[5]  + 1] =

    sl->ref_cache[0][scan8[7]  + 1] =

    sl->ref_cache[0][scan8[13] + 1] =

    sl->ref_cache[1][scan8[5]  + 1] =

    sl->ref_cache[1][scan8[7]  + 1] =

    sl->ref_cache[1][scan8[13] + 1] = PART_NOT_AVAILABLE;

    sl->er = &h->er;

}

static int h264_init_pic(H264Picture *pic)

{

    pic->f = av_frame_alloc();

    if (!pic->f)

        return AVERROR(ENOMEM);

    pic->f_grain = av_frame_alloc();

    if (!pic->f_grain)

        return AVERROR(ENOMEM);

    return 0;

}

static int h264_init_context(AVCodecContext *avctx, H264Context *h)

{

    int i, ret;

    h->avctx                 = avctx;

    h->cur_chroma_format_idc = -1;

    h->width_from_caller     = avctx->width;

    h->height_from_caller    = avctx->height;

    h->workaround_bugs       = avctx->workaround_bugs;

    h->flags                 = avctx->flags;

    h->poc.prev_poc_msb      = 1 << 16;

    h->recovery_frame        = -1;

    h->frame_recovered       = 0;

    h->poc.prev_frame_num    = -1;

    h->sei.common.frame_packing.arrangement_cancel_flag = -1;

    h->sei.common.unregistered.x264_build = -1;

    h->next_outputed_poc = INT_MIN;

    for (i = 0; i < FF_ARRAY_ELEMS(h->last_pocs); i++)

        h->last_pocs[i] = INT_MIN;

    ff_h264_sei_uninit(&h->sei);

    if (avctx->active_thread_type & FF_THREAD_FRAME) {

        h->decode_error_flags_pool = av_refstruct_pool_alloc(sizeof(atomic_int), 0);

        if (!h->decode_error_flags_pool)

            return AVERROR(ENOMEM);

    }

    h->nb_slice_ctx = (avctx->active_thread_type & FF_THREAD_SLICE) ? avctx->thread_count : 1;

    h->slice_ctx = av_calloc(h->nb_slice_ctx, sizeof(*h->slice_ctx));

    if (!h->slice_ctx) {

        h->nb_slice_ctx = 0;

        return AVERROR(ENOMEM);

    }

    for (i = 0; i < H264_MAX_PICTURE_COUNT; i++) {

        if ((ret = h264_init_pic(&h->DPB[i])) < 0)

            return ret;

    }

    if ((ret = h264_init_pic(&h->cur_pic)) < 0)

        return ret;

    if ((ret = h264_init_pic(&h->last_pic_for_ec)) < 0)

        return ret;

    for (i = 0; i < h->nb_slice_ctx; i++)

        h->slice_ctx[i].h264 = h;

    return 0;

}

static void h264_free_pic(H264Context *h, H264Picture *pic)

{

    ff_h264_unref_picture(pic);

    av_frame_free(&pic->f);

    av_frame_free(&pic->f_grain);

}

static av_cold int h264_decode_end(AVCodecContext *avctx)

{

    H264Context *h = avctx->priv_data;

    int i;

    ff_h264_remove_all_refs(h);

    ff_h264_free_tables(h);

    for (i = 0; i < H264_MAX_PICTURE_COUNT; i++) {

        h264_free_pic(h, &h->DPB[i]);

    }

    memset(h->delayed_pic, 0, sizeof(h->delayed_pic));

    h->cur_pic_ptr = NULL;

    av_refstruct_pool_uninit(&h->decode_error_flags_pool);

    av_freep(&h->slice_ctx);

    h->nb_slice_ctx = 0;

    ff_h264_sei_uninit(&h->sei);

    ff_h264_ps_uninit(&h->ps);

    ff_h2645_packet_uninit(&h->pkt);

    h264_free_pic(h, &h->cur_pic);

    h264_free_pic(h, &h->last_pic_for_ec);

    return 0;

}

static AVOnce h264_vlc_init = AV_ONCE_INIT;

static av_cold int h264_decode_init(AVCodecContext *avctx)

{

    H264Context *h = avctx->priv_data;

    int ret;

    ret = h264_init_context(avctx, h);

    if (ret < 0)

        return ret;

    ret = ff_thread_once(&h264_vlc_init, ff_h264_decode_init_vlc);

    if (ret != 0) {

        av_log(avctx, AV_LOG_ERROR, "pthread_once has failed.");

        return AVERROR_UNKNOWN;

    }

    if (!avctx->internal->is_copy) {

        if (avctx->extradata_size > 0 && avctx->extradata) {

            ret = ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,

                                           &h->ps, &h->is_avc, &h->nal_length_size,

                                           avctx->err_recognition, avctx);

           if (ret < 0) {

               int explode = avctx->err_recognition & AV_EF_EXPLODE;

               av_log(avctx, explode ? AV_LOG_ERROR: AV_LOG_WARNING,

                      "Error decoding the extradata\n");

               if (explode) {

                   return ret;

               }

               ret = 0;

           }

        }

    }

    if (h->ps.sps && h->ps.sps->bitstream_restriction_flag &&

        h->avctx->has_b_frames < h->ps.sps->num_reorder_frames) {

        h->avctx->has_b_frames = h->ps.sps->num_reorder_frames;

    }

    ff_h264_flush_change(h);

    if (h->enable_er < 0 && (avctx->active_thread_type & FF_THREAD_SLICE))

        h->enable_er = 0;

    if (h->enable_er && (avctx->active_thread_type & FF_THREAD_SLICE)) {

        av_log(avctx, AV_LOG_WARNING,

               "Error resilience with slice threads is enabled. It is unsafe and unsupported and may crash. "

               "Use it at your own risk\n");

    }

    return 0;

}

/**

 * instantaneous decoder refresh.

 */

static void idr(H264Context *h)

{

    int i;

    ff_h264_remove_all_refs(h);

    h->poc.prev_frame_num        =

    h->poc.prev_frame_num_offset = 0;

    h->poc.prev_poc_msb          = 1<<16;

    h->poc.prev_poc_lsb          = -1;

    for (i = 0; i < FF_ARRAY_ELEMS(h->last_pocs); i++)

        h->last_pocs[i] = INT_MIN;

}

/* forget old pics after a seek */

void ff_h264_flush_change(H264Context *h)

{

    int i, j;

    h->next_outputed_poc = INT_MIN;

    h->prev_interlaced_frame = 1;

    idr(h);

    h->poc.prev_frame_num = -1;

    if (h->cur_pic_ptr) {

        h->cur_pic_ptr->reference = 0;

        for (j=i=0; h->delayed_pic[i]; i++)

            if (h->delayed_pic[i] != h->cur_pic_ptr)

                h->delayed_pic[j++] = h->delayed_pic[i];

        h->delayed_pic[j] = NULL;

    }

    ff_h264_unref_picture(&h->last_pic_for_ec);

    h->first_field = 0;

    h->recovery_frame = -1;

    h->frame_recovered = 0;

    h->current_slice = 0;

    h->mmco_reset = 1;

}

static av_cold void h264_decode_flush(AVCodecContext *avctx)

{

    H264Context *h = avctx->priv_data;

    int i;

    memset(h->delayed_pic, 0, sizeof(h->delayed_pic));

    ff_h264_flush_change(h);

    ff_h264_sei_uninit(&h->sei);

    for (i = 0; i < H264_MAX_PICTURE_COUNT; i++)

        ff_h264_unref_picture(&h->DPB[i]);

    h->cur_pic_ptr = NULL;

    ff_h264_unref_picture(&h->cur_pic);

    h->mb_y = 0;

    h->non_gray = 0;

    ff_h264_free_tables(h);

    h->context_initialized = 0;

    if (FF_HW_HAS_CB(avctx, flush))

        FF_HW_SIMPLE_CALL(avctx, flush);

}

static int get_last_needed_nal(H264Context *h)

{

    int nals_needed = 0;

    int slice_type = 0;

    int picture_intra_only = 1;

    int first_slice = 0;

    int i, ret;

    for (i = 0; i < h->pkt.nb_nals; i++) {

        H2645NAL *nal = &h->pkt.nals[i];

        GetBitContext gb;

        /* packets can sometimes contain multiple PPS/SPS,

         * e.g. two PAFF field pictures in one packet, or a demuxer

         * which splits NALs strangely if so, when frame threading we

         * can't start the next thread until we've read all of them */

        switch (nal->type) {

        case H264_NAL_SPS:

        case H264_NAL_PPS:

            nals_needed = i;

            break;

        case H264_NAL_DPA:

        case H264_NAL_IDR_SLICE:

        case H264_NAL_SLICE:

            ret = init_get_bits8(&gb, nal->data + 1, nal->size - 1);

            if (ret < 0) {

                av_log(h->avctx, AV_LOG_ERROR, "Invalid zero-sized VCL NAL unit\n");

                if (h->avctx->err_recognition & AV_EF_EXPLODE)

                    return ret;

                break;

            }

            if (!get_ue_golomb_long(&gb) ||  // first_mb_in_slice

                !first_slice ||

                first_slice != nal->type)

                nals_needed = i;

            slice_type = get_ue_golomb_31(&gb);

            if (slice_type > 9)

                slice_type = 0;

            if (slice_type > 4)

                slice_type -= 5;

            slice_type = ff_h264_golomb_to_pict_type[slice_type];

            picture_intra_only &= (slice_type & 3) == AV_PICTURE_TYPE_I;

            if (!first_slice)

                first_slice = nal->type;

        }

    }

    h->picture_intra_only = picture_intra_only;

    return nals_needed;

}

static void debug_green_metadata(const H264SEIGreenMetaData *gm, void *logctx)

{

    av_log(logctx, AV_LOG_DEBUG, "Green Metadata Info SEI message\n");

    av_log(logctx, AV_LOG_DEBUG, "  green_metadata_type: %d\n", gm->green_metadata_type);

    if (gm->green_metadata_type == 0) {

        av_log(logctx, AV_LOG_DEBUG, "  green_metadata_period_type: %d\n", gm->period_type);

        if (gm->period_type == 2)

            av_log(logctx, AV_LOG_DEBUG, "  green_metadata_num_seconds: %d\n", gm->num_seconds);

        else if (gm->period_type == 3)

            av_log(logctx, AV_LOG_DEBUG, "  green_metadata_num_pictures: %d\n", gm->num_pictures);

        av_log(logctx, AV_LOG_DEBUG, "  SEI GREEN Complexity Metrics: %f %f %f %f\n",

               (float)gm->percent_non_zero_macroblocks/255,

               (float)gm->percent_intra_coded_macroblocks/255,

               (float)gm->percent_six_tap_filtering/255,

               (float)gm->percent_alpha_point_deblocking_instance/255);

    } else if (gm->green_metadata_type == 1) {

        av_log(logctx, AV_LOG_DEBUG, "  xsd_metric_type: %d\n", gm->xsd_metric_type);

        if (gm->xsd_metric_type == 0)

            av_log(logctx, AV_LOG_DEBUG, "  xsd_metric_value: %f\n",

                   (float)gm->xsd_metric_value/100);

    }

}

static int decode_nal_units(H264Context *h, AVBufferRef *buf_ref,

                            const uint8_t *buf, int buf_size)

{

    AVCodecContext *const avctx = h->avctx;

    int nals_needed = 0; ///< number of NALs that need decoding before the next frame thread starts

    int idr_cleared=0;

    int i, ret = 0;

    h->has_slice = 0;

    h->nal_unit_type= 0;

    if (!(avctx->flags2 & AV_CODEC_FLAG2_CHUNKS)) {

        h->current_slice = 0;

        if (!h->first_field) {

            h->cur_pic_ptr = NULL;

            ff_h264_sei_uninit(&h->sei);

        }

    }

    if (h->nal_length_size == 4) {

        if (buf_size > 8 && AV_RB32(buf) == 1 && AV_RB32(buf+5) > (unsigned)buf_size) {

            h->is_avc = 0;

        }else if(buf_size > 3 && AV_RB32(buf) > 1 && AV_RB32(buf) <= (unsigned)buf_size)

            h->is_avc = 1;

    }

    ret = ff_h2645_packet_split(&h->pkt, buf, buf_size, avctx, h->nal_length_size,

                                avctx->codec_id, !!h->is_avc * H2645_FLAG_IS_NALFF);

    if (ret < 0) {

        av_log(avctx, AV_LOG_ERROR,

               "Error splitting the input into NAL units.\n");

        return ret;

    }

    if (avctx->active_thread_type & FF_THREAD_FRAME)

        nals_needed = get_last_needed_nal(h);

    if (nals_needed < 0)

        return nals_needed;

    for (i = 0; i < h->pkt.nb_nals; i++) {

        H2645NAL *nal = &h->pkt.nals[i];

        int max_slice_ctx, err;

        if (avctx->skip_frame >= AVDISCARD_NONREF &&

            nal->ref_idc == 0 && nal->type != H264_NAL_SEI)

            continue;

        // FIXME these should stop being context-global variables

        h->nal_ref_idc   = nal->ref_idc;

        h->nal_unit_type = nal->type;

        err = 0;

        switch (nal->type) {

        case H264_NAL_IDR_SLICE:

            if ((nal->data[1] & 0xFC) == 0x98) {

                av_log(h->avctx, AV_LOG_ERROR, "Invalid inter IDR frame\n");

                h->next_outputed_poc = INT_MIN;

                ret = -1;

                goto end;

            }

            if(!idr_cleared) {

                idr(h); // FIXME ensure we don't lose some frames if there is reordering

            }

            idr_cleared = 1;

            h->has_recovery_point = 1;

        case H264_NAL_SLICE:

            h->has_slice = 1;

            if ((err = ff_h264_queue_decode_slice(h, nal))) {

                H264SliceContext *sl = h->slice_ctx + h->nb_slice_ctx_queued;

                sl->ref_count[0] = sl->ref_count[1] = 0;

                break;

            }

            if (h->current_slice == 1) {

                if (avctx->active_thread_type & FF_THREAD_FRAME &&

                    i >= nals_needed && !h->setup_finished && h->cur_pic_ptr) {

                    ff_thread_finish_setup(avctx);

                    h->setup_finished = 1;

                }

                if (h->avctx->hwaccel &&

                    (ret = FF_HW_CALL(h->avctx, start_frame, buf_ref,

                                      buf, buf_size)) < 0)

                    goto end;

            }

            max_slice_ctx = avctx->hwaccel ? 1 : h->nb_slice_ctx;

            if (h->nb_slice_ctx_queued == max_slice_ctx) {

                if (h->avctx->hwaccel) {

                    ret = FF_HW_CALL(avctx, decode_slice, nal->raw_data, nal->raw_size);

                    h->nb_slice_ctx_queued = 0;

                } else

                    ret = ff_h264_execute_decode_slices(h);

                if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))

                    goto end;

            }

            break;

        case H264_NAL_DPA:

        case H264_NAL_DPB:

        case H264_NAL_DPC:

            avpriv_request_sample(avctx, "data partitioning");

            break;

        case H264_NAL_SEI:

            if (h->setup_finished) {

                avpriv_request_sample(avctx, "Late SEI");

                break;

            }

            ret = ff_h264_sei_decode(&h->sei, &nal->gb, &h->ps, avctx);

            h->has_recovery_point = h->has_recovery_point || h->sei.recovery_point.recovery_frame_cnt != -1;

            if (avctx->debug & FF_DEBUG_GREEN_MD)

                debug_green_metadata(&h->sei.green_metadata, h->avctx);

            if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))

                goto end;

            break;

        case H264_NAL_SPS: {

            GetBitContext tmp_gb = nal->gb;

            if (FF_HW_HAS_CB(avctx, decode_params)) {

                ret = FF_HW_CALL(avctx, decode_params,

                                 nal->type, nal->raw_data, nal->raw_size);

                if (ret < 0)

                    goto end;

            }

            if (ff_h264_decode_seq_parameter_set(&tmp_gb, avctx, &h->ps, 0) >= 0)

                break;

            av_log(h->avctx, AV_LOG_DEBUG,

                   "SPS decoding failure, trying again with the complete NAL\n");

            init_get_bits8(&tmp_gb, nal->raw_data + 1, nal->raw_size - 1);

            if (ff_h264_decode_seq_parameter_set(&tmp_gb, avctx, &h->ps, 0) >= 0)

                break;

            ff_h264_decode_seq_parameter_set(&nal->gb, avctx, &h->ps, 1);

            break;

        }

        case H264_NAL_PPS:

            if (FF_HW_HAS_CB(avctx, decode_params)) {

                ret = FF_HW_CALL(avctx, decode_params,

                                 nal->type, nal->raw_data, nal->raw_size);

                if (ret < 0)

                    goto end;

            }

            ret = ff_h264_decode_picture_parameter_set(&nal->gb, avctx, &h->ps,

                                                       nal->size_bits);

            if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))

                goto end;

            break;

        case H264_NAL_AUD:

        case H264_NAL_END_SEQUENCE:

        case H264_NAL_END_STREAM:

        case H264_NAL_FILLER_DATA:

        case H264_NAL_SPS_EXT:

        case H264_NAL_AUXILIARY_SLICE:

            break;

        default:

            av_log(avctx, AV_LOG_DEBUG, "Unknown NAL code: %d (%d bits)\n",

                   nal->type, nal->size_bits);

        }

        if (err < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE)) {

            av_log(h->avctx, AV_LOG_ERROR, "decode_slice_header error\n");

            ret = err;

            goto end;

        }

    }

    ret = ff_h264_execute_decode_slices(h);

    if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))

        goto end;

    // set decode_error_flags to allow users to detect concealed decoding errors

    if ((ret < 0 || h->er.error_occurred) && h->cur_pic_ptr) {

        if (h->cur_pic_ptr->decode_error_flags) {

            /* Frame-threading in use */

            atomic_int *decode_error = h->cur_pic_ptr->decode_error_flags;

            /* Using atomics here is not supposed to provide synchronisation;

             * they are merely used to allow to set decode_error from both

             * decoding threads in case of coded slices. */

            atomic_fetch_or_explicit(decode_error, FF_DECODE_ERROR_DECODE_SLICES,

                                     memory_order_relaxed);

        } else

            h->cur_pic_ptr->f->decode_error_flags |= FF_DECODE_ERROR_DECODE_SLICES;

    }

    ret = 0;

end:

#if CONFIG_ERROR_RESILIENCE

    /*

     * FIXME: Error handling code does not seem to support interlaced

     * when slices span multiple rows

     * The ff_er_add_slice calls don't work right for bottom

     * fields; they cause massive erroneous error concealing

     * Error marking covers both fields (top and bottom).

     * This causes a mismatched s->error_count

     * and a bad error table. Further, the error count goes to

     * INT_MAX when called for bottom field, because mb_y is

     * past end by one (callers fault) and resync_mb_y != 0

     * causes problems for the first MB line, too.

     */

    if (!FIELD_PICTURE(h) && h->current_slice && h->enable_er) {

        H264SliceContext *sl = h->slice_ctx;

        int use_last_pic = h->last_pic_for_ec.f->buf[0] && !sl->ref_count[0];

        int decode_error_flags = 0;

        ff_h264_set_erpic(&h->er.cur_pic, h->cur_pic_ptr);

        if (use_last_pic) {

            ff_h264_set_erpic(&h->er.last_pic, &h->last_pic_for_ec);

            sl->ref_list[0][0].parent = &h->last_pic_for_ec;

            memcpy(sl->ref_list[0][0].data, h->last_pic_for_ec.f->data, sizeof(sl->ref_list[0][0].data));

            memcpy(sl->ref_list[0][0].linesize, h->last_pic_for_ec.f->linesize, sizeof(sl->ref_list[0][0].linesize));

            sl->ref_list[0][0].reference = h->last_pic_for_ec.reference;

        } else if (sl->ref_count[0]) {

            ff_h264_set_erpic(&h->er.last_pic, sl->ref_list[0][0].parent);

        } else

            ff_h264_set_erpic(&h->er.last_pic, NULL);

        if (sl->ref_count[1])

            ff_h264_set_erpic(&h->er.next_pic, sl->ref_list[1][0].parent);

        ff_er_frame_end(&h->er, &decode_error_flags);

        if (decode_error_flags) {

            if (h->cur_pic_ptr->decode_error_flags) {

                atomic_int *decode_error = h->cur_pic_ptr->decode_error_flags;

                atomic_fetch_or_explicit(decode_error, decode_error_flags,

                                         memory_order_relaxed);

            } else

                h->cur_pic_ptr->f->decode_error_flags |= decode_error_flags;

        }

        if (use_last_pic)

            memset(&sl->ref_list[0][0], 0, sizeof(sl->ref_list[0][0]));

    }

#endif /* CONFIG_ERROR_RESILIENCE */

    /* clean up */

    if (h->cur_pic_ptr && !h->droppable && h->has_slice) {

        ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,

                                  h->picture_structure == PICT_BOTTOM_FIELD);

    }

    return (ret < 0) ? ret : buf_size;

}

static int h264_export_enc_params(AVFrame *f, const H264Picture *p)

{

    AVVideoEncParams *par;

    unsigned int nb_mb = p->mb_height * p->mb_width;

    unsigned int x, y;

    par = av_video_enc_params_create_side_data(f, AV_VIDEO_ENC_PARAMS_H264, nb_mb);

    if (!par)

        return AVERROR(ENOMEM);

    par->qp = p->pps->init_qp;

    par->delta_qp[1][0] = p->pps->chroma_qp_index_offset[0];

    par->delta_qp[1][1] = p->pps->chroma_qp_index_offset[0];

    par->delta_qp[2][0] = p->pps->chroma_qp_index_offset[1];

    par->delta_qp[2][1] = p->pps->chroma_qp_index_offset[1];

    for (y = 0; y < p->mb_height; y++)

        for (x = 0; x < p->mb_width; x++) {

            const unsigned int block_idx = y * p->mb_width + x;

            const unsigned int     mb_xy = y * p->mb_stride + x;

            AVVideoBlockParams *b = av_video_enc_params_block(par, block_idx);

            b->src_x = x * 16;

            b->src_y = y * 16;

            b->w     = 16;

            b->h     = 16;

            b->delta_qp = p->qscale_table[mb_xy] - par->qp;

        }

    return 0;

}

static int output_frame(H264Context *h, AVFrame *dst, H264Picture *srcp)

{

    int ret;

    ret = av_frame_ref(dst, srcp->needs_fg ? srcp->f_grain : srcp->f);

    if (ret < 0)

        return ret;

    if (srcp->needs_fg && (ret = av_frame_copy_props(dst, srcp->f)) < 0)

        return ret;

    if (srcp->decode_error_flags) {

        atomic_int *decode_error = srcp->decode_error_flags;

        /* The following is not supposed to provide synchronisation at all:

         * given that srcp has already finished decoding, decode_error

         * has already been set to its final value. */

        dst->decode_error_flags |= atomic_load_explicit(decode_error, memory_order_relaxed);

    }

    av_dict_set(&dst->metadata, "stereo_mode", ff_h264_sei_stereo_mode(&h->sei.common.frame_packing), 0);

    if (srcp->sei_recovery_frame_cnt == 0)

        dst->flags |= AV_FRAME_FLAG_KEY;

    if (h->avctx->export_side_data & AV_CODEC_EXPORT_DATA_VIDEO_ENC_PARAMS) {

        ret = h264_export_enc_params(dst, srcp);

        if (ret < 0)

            goto fail;

    }

    if (!(h->avctx->export_side_data & AV_CODEC_EXPORT_DATA_FILM_GRAIN))

        av_frame_remove_side_data(dst, AV_FRAME_DATA_FILM_GRAIN_PARAMS);

    return 0;

fail:

    av_frame_unref(dst);

    return ret;

}

static int is_avcc_extradata(const uint8_t *buf, int buf_size)

{

    int cnt= buf[5]&0x1f;

    const uint8_t *p= buf+6;

    if (!cnt)

        return 0;

    while(cnt--){

        int nalsize= AV_RB16(p) + 2;

        if(nalsize > buf_size - (p-buf) || (p[2] & 0x9F) != 7)

            return 0;

        p += nalsize;

    }

    cnt = *(p++);

    if(!cnt)

        return 0;

    while(cnt--){

        int nalsize= AV_RB16(p) + 2;

        if(nalsize > buf_size - (p-buf) || (p[2] & 0x9F) != 8)

            return 0;

        p += nalsize;

    }

    return 1;

}

static int finalize_frame(H264Context *h, AVFrame *dst, H264Picture *out, int *got_frame)

{

    int ret;

    if (((h->avctx->flags & AV_CODEC_FLAG_OUTPUT_CORRUPT) ||

         (h->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL) ||

         out->recovered)) {

        if (h->skip_gray > 0 &&

            h->non_gray && out->gray &&

            !(h->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL)

        )

            return 0;

        if (!h->avctx->hwaccel &&

            (out->field_poc[0] == INT_MAX ||

             out->field_poc[1] == INT_MAX)

           ) {

            int p;

            AVFrame *f = out->f;

            int field = out->field_poc[0] == INT_MAX;

            uint8_t *dst_data[4];

            int linesizes[4];

            const uint8_t *src_data[4];

            av_log(h->avctx, AV_LOG_DEBUG, "Duplicating field %d to fill missing\n", field);

            for (p = 0; p<4; p++) {

                dst_data[p] = f->data[p] + (field^1)*f->linesize[p];

                src_data[p] = f->data[p] +  field   *f->linesize[p];

                linesizes[p] = 2*f->linesize[p];

            }

            av_image_copy(dst_data, linesizes, src_data, linesizes,

                          f->format, f->width, f->height>>1);

        }

        ret = output_frame(h, dst, out);

        if (ret < 0)

            return ret;

        *got_frame = 1;

        if (CONFIG_MPEGVIDEODEC) {

            ff_print_debug_info2(h->avctx, dst,

                                 out->mb_type,

                                 out->qscale_table,

                                 out->motion_val,

                                 out->mb_width, out->mb_height, out->mb_stride, 1);

        }

    }

    return 0;

}

static int send_next_delayed_frame(H264Context *h, AVFrame *dst_frame,

                                   int *got_frame, int buf_index)

{

    int ret, i, out_idx;

    H264Picture *out;